DRAKE 300VMFPLUS Руководство по эксплуатации - Страница 3
Просмотреть онлайн или скачать pdf Руководство по эксплуатации для Модулятор DRAKE 300VMFPLUS. DRAKE 300VMFPLUS 10 страниц. Commercial video modulator (for use in ntsc systems)
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TABLE OF CONTENTS
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Table of Contents / General Description
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Specifications
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Front Panel Controls, Indicators, and
DESCRIPTION
The DRACOM 300VMF+ Video Modulator is a vestigial
sideband heterodyne audio/video modulator that
provides a modulated visual and aural RF carrier output
on any single EIA standard channel from channel 2
through channel 78 plus channels 95 to 99. This range
covers 54 through 552 MHz. Consult factory for custom
channels. All aeronautical channels are offset positive
with a tolerance of ±5 kHz as required by FCC rules. The
300VMF+ is designed to accept video and audio
SPECIFICATIONS
RF
Frequency Range:
54 - 552 MHz.
Channels Available:
Factory ordered for a single channel:
EIA CATV channels 2 to 78 and 95 to 99.
FCC Frequency
Offsets:
All aeronautical channels offset positive
with a tolerance of ±5 kHz.
Output Level:
+55 dBmV, (typically adjustable from +43
to +55 dBmV).
Output Impedance:
75 OHMS, return loss of 14 dB, nominal.
Output Test:
-30 dB, ±3 dB (referenced to
RF OUTPUT level).
A/V Ratio:
Audio Carrier -20 to -12 dB referenced to
video carrier, adjustable.
Frequency Stability,
Visual:
Within ±10 kHz of assigned channel
frequency; ±5 kHz on FCC
offset channels.
Aural Intercarrier
Frequency:
4.5 MHz, ±5 kHz.
Spurious Outputs:
-60 dBc minimum, measured at -15 dB A/V
ratio and with modulator output level of
+55 dBmV.
In-Channel C/N:
Better than 60 dB.
Broadband Noise:
-95 dBc @ ±30 MHz or
greater spacings. (Specified levels are
referenced to the video carrier and
measured in a 4 MHz bandwidth).
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Rear Panel Connections and Internal Jumper
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baseband signals from a satellite receiver, TV camera,
video tape recorder, TV demodulator or similar
equipment. The heterodyne conversion system, in
conjunction with the use of a SAW filter, insures optimum
vestigial selectivity for adjacent channel headends.
The modulator accepts standard (sync negative) polarity
video at a 0.7 -1.5 Vpp level. All level controls are
located on the front panel for ease of operation.
VIDEO
Input level for 87.5%
Modulation:
1 Vp-p ±3 dB, manual gain adjust with
front panel control.
Input Impedance:
75 Ohms, return loss of 18 dB
minimum.
Frequency Response:
Flat ±2 dB from 30 Hz to 4.2 MHz.
Video S/N:
60 dB, luminance weighted.
L/C Delay:
Within 50 nSec of 0 nSec L/C delay
(complies with FCC rules, 76.605).
Differential Gain:
Less than ±5% (10 to 90% APL).
Differential Phase:
Less than ±5 degrees (10 to 90% APL).
AUDIO
Input Level for
25 kHz Peak Deviation:
175 mV rms minimum. Manual gain
adjustment with front panel control.
Input Impedance:
10K Ohms, unbalanced.
Pre-emphasis:
75 Sec.(flat by moving internal jumper)
Frequency Response:
40 Hz to 15 kHz, ±1.5 dB, referenced to
75 Sec pre-emphasis curve.
4.5 MHz Intercarrier Stability:
Within ±5 kHz, 0
Total Harmonic Distortion:
1.5% maximum.
Hum and Noise:
-60 dB minimum, referenced
to 25 kHz peak deviation.
GENERAL
Modulator Power
Requirement:
115 VAC ±10%, 60Hz, 10 Watts.
Auxiliary AC Outlet:
Nominal 120 VAC, 600 Watts, maximum.
Total AC Power Input:
Nominal 120 VAC 60 Hz,
610 Watts, maximum.
Operating Temperature
Range:
0
Size:
19" W x 1.75" H x 4.0" D.
Weight:
3.6 lbs.
Connectors:
Video input, Audio input, RF output, and
Monitor output are all type F.
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0
C to +50
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C.
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C to +50
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C, ambient.